With the advent of the electronic age, bar codes and bar code scanning systems became the primary means for identifying, tracking, cataloging and otherwise managing objects of various sizes in a variety of different industries and applications. Grocery, food processing and retail industries, assembly lines and warehouses, among many others, utilize bar codes to store information, either directly on the items, or on printed labels that are attached or associated with the items.
Bar codes typically consist of a series of lines and spaces of various widths, or other types of symbols comprised of a series of contrasting markings. These contrasting markings usually represent strings of binary ones and zeroes. These patterns are read by a number of different bar code readers, hand-held wands and laser scanning systems that have been developed to capture and decode the symbol pattern to a numeric or alphanumeric representation for inventory, production tracking, check-out or sales purposes. One common example of a bar code is the Universal Product Code (UPC).
Most point-of-sale systems that utilize bar codes, such as retail stores and supermarkets, or factories, warehouses and other businesses utilize stationary laser-based bar code readers or scanners. The scanners are generally installed in or on the check-out counter and thus take up some otherwise useful physical space at the counter. These types of systems also are often installed, at least in part, within the physical housing. For example, in-counter slot scanners typically have glass exit windows in the same horizontal plane as the counter. One of the drawbacks of utilizing these scanners is that the debris and dirt that accumulate on the horizontal plane can scratch, damage, or otherwise obscure the glass surface, degrading performance of the scanner and possibly causing malfunctions. Moreover, the addition of such a scanning system to a check-out station requires specialized and often expensive installation to provide custom-made surfaces, cut-outs, etc. at the counter where scanning is performed. Even if the check-out station is constructed initially with cut-outs and other features designed to accept a scanning system, such features can severely limit the use of the check-out counter for non-scanning purposes.
Another shortcoming of the bar code readers that are utilized with existing point-of-sale systems is that they require the operator to visually locate the bar code on the item that is being scanned and to position it in the scanner's field of view. For example, when the scanner is installed on the opposite side of a check-out counter, the operator must rotate the surface containing the bar code away from himself and toward the field of view of the scanner. Bi-optic or multi-planer scanning systems, which typically have two (or more) active “sides” (i.e. able to scan a bar code on both the bottom surface and from the side) alleviate the need to rotate the object toward the scanner. They are very expensive, however, and overly complex in their installation and maintenance.
In addition to laser-based scanning, some camera-based scanning systems are known. These systems use conveyer belts to move and scan items with bar codes, such as inventory or mail, past the scanning system at high rates of speed. These scanning systems rely upon the automated conveyor and other automated systems to accurately place items to be scanned within the proper field of view of the scanning camera system. Such large-scale conveyor scanning systems are too expensive and impractical for use in a typical point-of-sale environment. Moreover, automated item placement by a conveyor and other systems is generally not available in a point-of-sale. Instead, establishments rely upon typically untrained customers to manually scan items. Thus, additional mechanisms are necessary to aid users in correctly placing items during the scanning process.
Some known point-of-sale self-checkout scanning systems for use by customers in a retail environment include a camera. Such a system is disclosed, for example, in U.S. Pat. Nos. 5,965,861 and 6,236,736. However, such systems do not use the camera to detect and process the bar-code on the items. Instead, a conventional in-counter laser-based scanning system is provided which has the drawbacks discussed above. The camera system is used to provide additional security, e.g., by tracking the motions of a customer's hand to detect scanning-type motions or to detect when items have been placed in a bag before it has been scanned.